Systemic therapy response evaluation in prostate carcinoma with [ 68 Ga]Ga-PSMA-11 PET/CT

Background Consensus statements was published by EAU and EANM to clarify some uncertainties on PSMA PET/CT response assessment in 2020. We aimed to investigate the response criteria for PSMA PET/CT according to published criteria by comparing with serum PSA changes and determine the factors affecting therapy response evaluation. Results A high concordance was found between [ 68 Ga]Ga-PSMA-11 PET/CT and serum PSA responses and 0.84 of Gamma coefficient was obtained. Between concordant and discordant group, statistically significant difference was not found in terms of received therapies and castration resistance status. Statistically significant but low correlation was found between serum PSA and SUV values of prostate, moderate correlation was found serum PSA and SUVmax values of metastatic lymph nodes and bones. Conclusions The response evaluation of PSMA PET/CT according to the published criteria shows high concordance with serum PSA values without being affected by received therapies or castration resistance. This criteria can be used with contribution of serum PSA values in response evaluation of prostate cancer according to our results and literature data.